Method of producing copolymerized polycarbonates

ABSTRACT

The object of the present invention is to provide a method of producing copolymerized polycarbonates having improved flow and formability, in addition to excellent mechanical properties, heat resistance, transparency, and color tone. A method of producing copolymerized polycarbonates by melt polycondensation of two or more aromatic dihydroxy compounds with a carbonate diester, characterized in that (i) resorcin and/or substituted resorcins are used as 2-90 mole % of the aromatic dihydroxy compounds, where the sum of all the aromatic dihydroxy compounds is taken as 100 mole %, and (ii) an alkali metal compound and/or an alkaline-earth metal compound (a) is used as the catalyst.

This is a divisional of application Ser. No. 08/116,304 filed on Sep. 3,1993, now U.S. Pat. No. 5,384,388 which is a continuation application ofSer. No. 07/863,922 Apr. 6, 1992, now abandoned.

DETAILED EXPLANATION OF INVENTION

1. Technical Field of Invention

The present invention relates to a method of producing copolymerizedpolycarbonates, specifically to a method of producing copolymerizedpolycarbonates having improved formability and flow during forming, inaddition to excellent mechanical properties, heat resistance,transparency, and color tone.

2. Technical Background of Invention

Polycarbonates have excellent impact resistance and other mechanicalproperties as well as good heat resistance, transparency, etc. They arewidely used in various types of machine parts, optical disks, automobileparts, etc.

Conventional polycarbonates having such properties are usually producedby interfacial polymerization, in which an aromatic dihydroxy compoundsuch as bisphenol A reacts directly with phosgene. Polycarbonates thistype have high glass transition temperatures (T_(g)), and when they aremelt formed into optical disks, etc., their fluidity is increased bymelting them at high temperatures.

Molded products of polymers in general, and polycarbonates inparticular, are more prone to show effects such as impaired transparencyand discoloration the longer the material remains in molten form at hightemperatures during molding.

Thus, if the melt flow of polycarbonates could be improved, the lengthof time they are kept in a molten state could be shortened, thus givingmolded products which are less affected by heat during forming. Theforming characteristics of the polymers would also be improved in otherrespects, such as shorter molding cycle times and better productivity.Thus there has been a demand for polycarbonates which show even betterflow and formability without sacrificing the inherent advantages ofpolycarbonates such as their mechanical properties, heat resistance,transparency, and color tone.

As a result of determined research by the present inventors seeking toobtain polycarbonates with improved flow and formability without loss ofmechanical properties, heat resistance, transparency, or color tone, ithas been found that copolymerized polycarbonates formed by meltpolycondensation of aromatic dihydroxy compounds containing resorcinand/or substituted resorcins with carbonate diesters show Just suchexcellent properties. That discovery has led to the present invention.

OBJECT OF INVENTION

The present invention has been developed with the above-mentionedproblems of the prior art in mind. Its object is to provide a method ofproducing copolymerized polycarbonates having improved flow andformability in addition to excellent mechanical properties, heatresistance, transparency, and color tone.

SUMMARY OF INVENTION

The method of producing copolymerized polycarbonates by meltpolycondensation of two or more aromatic dihydroxy compounds and acarbonate diester in accordance with the present invention ischaracterized in that

(i) if the total amount of aromatic dihydroxy compounds used is 100 mole%, resorcin and/or substituted resorcins make up 2-90 mole % of thattotal, and

(ii) an alkali metal compound and/or alkaline-earth metal compound (a)is used as the catalyst.

In the method of producing copolymerized polycarbonates in accordancewith the present invent ion, the amount of alkali metal compound and/oralkaline-earth metal compound (a) used is preferably 1×10⁻⁸ to 1×10⁻³mole, more preferably 1×10⁻⁷ to 2.5×10⁻⁶ mole, per mole of aromaticdihydroxy compounds.

The catalyst used is preferably a combination of

(a) an alkali metal compound and/or alkaline-earth metal compound,

(b) a nitrogen-containing basic compound, and

(c) boric acid or a borate ester.

Also, in the method of producing copolymerized polycarbonates inaccordance with the present invention, an acidic compound and optionallyan epoxy compound are preferably added to the reaction product obtainedby melt polycondensation, which is then subjected to a vacuum treatment.

SPECIFIC EXPLANATION OF INVENTION

The method of producing copolymerized polycarbonates in accordance withthe present invention will now be explained in detail.

In accordance with the present invention, copolymerized polycarbonatesare produced by melt polycondensation of two or more aromatic dihydroxycompounds with a carbonate diester.

One of the aromatic dihydroxy compounds used is resorcin or asubstituted resorcin.

The resorcin and/or substituted resorcins used in the present inventionare represented by the following general formula I!. ##STR1##

In the formula I!, each R is a C₁₋₁₀ hydrocarbyl group or halogenatedhydrocarbyl group, or a halogen atom. n is an integer from 0 to 4. Whenn is 2 or more, the various R groups may be the same or different.

Specific examples of such substituted resorcins include3-methylresorcin, 3-ethylresorcin, 3-propylresorcin, 3-butylresorcin,3-tert-butylresorcin, 3-phenylresorcin, 3-cumylresorcin,2,3,4,5-tetrafluororesorcin, 2,3,4,5-tetrabromoresorcin, etc.

These compounds may be used singly or in combinations.

Of the various compounds of this type, resorcin is preferably used.

In the production of copolymerized polycarbonates in accordance with thepresent invention, if the total amount of aromatic dihydroxy compoundsused is 100 mole %, the amount of resorcin and/or substituted resorcinsshould be 2-90 mole %, preferably 5-70 mole %, more preferably 10-60mole %, of the total.

The amount of aromatic dihydroxy compounds other than resorcin and/orsubstituted resorcins used should be 98-10 mole %, preferably 95-30 mole%, more preferably 90-40 mole %.

There is no particular restriction on the aromatic dihydroxy compoundsother than resorcin and/or substituted resorcins which may be used; theymay be any compound represented by the following general formula II!, orcompounds of that general formula II! in which the phenyl rings aresubstituted with aliphatic groups and/or halogen atoms. ##STR2## (whereB is ##STR3## --O--, --S--, --SO-- or --SO₂ --, R¹ and R² are hydrogenatoms or monovalent hydrocarbyl groups, R³ is a divalent hydrocarbylenegroup, and R⁴ and R⁵ are halogen atoms or monovalent hydrocarbyl groups,each of which may be the same as or different from the others, and p andq are both integers from 0 to 4).

Examples of such aromatic dihydroxy compounds include:

bis(4-hydroxyphenyl)methane,

1,1-bis(4-hydroxyphenyl)ethane,

2,2-bis(4-hydroxyphenyl)propane,

2,2-bis(4-hydroxyphenyl)butane,

2,2-bis(4-hydroxyphenyl)octane,

bis(4-hydroxyphenyl)phenylmethane,

2,2-bis(4-hydroxy-1-methylphenyl)propane,

1,1-bis(4-hydroxy-tert-butylphenyl)propane,

2,2-bis(4-hydroxy-3-bromophenyl)propane, and other bis(hydroxy aryl)alkanes,

1,1-bis(4-hydroxyphenyl)cyclopentane,

1,1-bis(4-hydroxyphenyl)cyclohexane, and other bis(hydroxyaryl)cycloalkanes,

4,4'-dihydroxydiphenyl ether,

4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, and other dihydroxy arylethers,

4,4'-dihydroxydiphenyl sulfide,

4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, and other dihydroxy diarylsulfides,

4,4'-dihydroxydiphenyl sulfoxide,

4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, and other dihydroxydiaryl sulfoxides, and

4,4'-dihydroxydiphenyl sulfone,

4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone, and other dihydroxy diarylsulfones.

Of the various compounds of this type, 2,2-bis(4-hydroxyphenyl)propaneis preferably used.

Specific examples of carbonate diesters which may be used include:

diphenyl carbonate,

ditolyl carbonate,

bis(chlorophenyl) carbonate,

m-cresyl carbonate sic!,

dinaphthyl carbonate,

bis(diphenyl) carbonate,

diethyl carbonate,

dimethyl carbonate,

dibutyl carbonate,

dicyclohexyl carbonate, etc.

Of the various compounds of this type, diphenyl carbonate is preferablyused.

These carbonate diesters may also contain up to 50 mole %, preferablynot more than 30 mole %, dicarboxylic acids or their derivatives.

Specific examples of dicarboxylic acids or their derivatives include:

dicarboxylic acids, such as terephthalic acid, isophthalic acid, sebacicacid, decanedioic acid, dodecanedioic acid, etc.,

dicarboxylic acid esters, such as diphenyl sebacate, diphenylterephthalate, diphenyl isophthalate, diphenyl decanedioate, diphenyldodecanedioate, etc., and

dicarboxylic acid halides, such as terephthaloyl chloride, isophthaloylchloride, sebacoyl chloride, decanedioyl chloride, dodecanedioylchloride, etc.

When carbonate diesters containing such dicarboxylic acids or theirderivatives are polycondensed with the above-mentioned aromaticdihydroxy compounds, polyester-polycarbonate units are obtained.

In the production of copolymerized polycarbonates in accordance with thepresent invention, the amount of such carbonate diesters used should be1.0-1.3 moles, preferably 1.01-1.20 moles, per mole of aromaticdihydroxy compounds.

In addition to the sort of aromatic dihydroxy compounds and carbonatediesters described above, polyfunctional compounds having three or morefunctional groups per molecule can also be used.

The polyfunctional compounds are preferably compounds having three ormore phenolic hydroxyl groups or carboxyl groups. It is particularlypreferred to use compounds having three or more phenolic hydroxylgroups. Specific examples include:

1,1,1-tris(4-hydroxyphenyl)ethane,

2,2',2"-tris (4-hydroxyphenyl)diisopropylbenzene,

α-methyl-α,α',α'-tris(4-hydroxyphenyl)-1,4-diethylbenzene,

α,α',α"-tris(4-hydroxyphenyl)-1,3,5-triisopropylbenzene,

fluoroglycin,

4,6-dimethyl-2,4,6-tri(4-hydroxyphenyl)heptane-2,

1,3,5-tri(4-hydroxyphenyl)benzene,

2,2-bis 4,4-(4,4'-dihydroxyphenyl)cyclohexyl!propane,

trimellitic acid,

1,3,5-benzenetricarboxylic acid,

pyromellitic acid, etc.

Preferred among these compounds are 1,1,1-tris(4-hydroxyphenyl)ethane,α,α',α"-tris(4-hydroxyphenyl)1,3,5-triisopropylbenzene, etc.

When polyfunctional compounds are used, the amount is usually not morethan 0.03 mole, preferably 0.001-0.02 mole, more preferably 0.001-0.01mole, per mole of aromatic dihydroxy compounds.

In accordance with the present invention, copolymerized polycarbonatesare produced by melt polycondensation of aromatic dihydroxy compoundsincluding resorcin and/or substituted resorcins as described above withcarbonate diesters in the presence of a catalyst.

An alkali metal compound and/or an alkaline-earth metal compound (a) isused as the catalyst.

Examples of such an alkali metal compound and/or alkaline-earth metalcompound (a) include salts of alkali metals or alkaline-earth metalswith organic acids or inorganic acids, as well as alkali metal andalkaline-earth metal oxides, hydroxides, hydrides, alcoholates, etc.

Specifically, alkali metal compounds which may be used include sodiumhydroxide, potassium hydroxide, lithium hydroxide, sodium hydrogencarbonate, potassium hydrogen carbonate, lithium hydrogen carbonate,sodium carbonate, potassium carbonate, lithium carbonate, sodiumacetate, potassium acetate, lithium acetate, sodium stearate, potassiumstearate, lithium stearate, sodium borohydride, lithium borohydride,sodium phenylborate, sodium benzoate, potassium benzoate, lithiumbenzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate,dilithium hydrogen phosphate, bisphenol A disodium salt, bisphenol Adipotassium salt, bisphenol A dilithium salt, sodium phenolate,potassium phenolate, lithium phenolate, etc.

Specific alkaline-earth metal salts which may be used include calciumhydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide,calcium hydrogen carbonate, barium hydrogen carbonate, magnesiumhydrogen carbonate, strontium hydrogen carbonate, calcium carbonate,barium carbonate, magnesium carbonate, strontium carbonate, calciumacetate, barium acetate, magnesium acetate, strontium acetate, calciumstearate, barium stearate, magnesium stearate, strontium stearate, etc.

These compounds may be used singly or in combinations.

The amount of alkali metal compound and/or alkaline-earth metal compound(a) used is generally not more than (1×10⁻² mole), preferably 1×10⁻⁸ to1×10⁻³ mole, more preferably 1×10⁻⁷ to 1×10⁻⁵ mole, most preferably1×10⁻⁷ to 2.5×10⁻⁶ mole, per mole of aromatic dihydroxy compounds.

If the amount of alkali metal compound and/or alkaline-earth metalcompound (a) used is 1×10⁻⁸ to 1×10⁻³ mole per mole of aromaticdihydroxy compounds, the basicity of those compounds can be weakened orcompletely neutralized by adding acidic compounds (described below) inamounts which serve to maintain high polymerization activity while notadversely affecting the properties of the resulting copolymerizedpolycarbonate. In this way one can obtain copolymerized polycarbonateshaving excellent color tone, heat resistance, water resistance, weatherresistance, and stability when kept in a molten state for long periodsof time.

The catalyst used in accordance with the present invention may be acombination of an alkali metal compound and/or alkaline-earth metalcompound (a), as described above, with a basic compound (b), and/or aborate compound (c).

Examples of such a basic compound (b) include nitrogen compounds whichare easily decomposed or volatilized at high temperatures. Specificcompounds of this type include the following.

Alkyl, aryl, and/or alkaryl group-containing ammonium hydroxides, suchas tetramethylammonium hydroxide (Me₄ NOH), tetraethylammonium hydroxide(Et₄ NOH), tetrabutylammonium hydroxide (Bu₄ NOH),trimethylbenzylammonium hydroxide (φ-CH₂ (Me)₃ NOH), etc.,

tertiary amines, such as trimethylamine, triethylamine,dimethylbenzylamine, triphenylamine, etc.,

secondary amines represented by R₂ NH (where R is an alkyl group such asmethyl, ethyl, etc., or an aryl group such as phenyl, tolyl, etc.),

primary amines represented by RNH₂ (where R is as above),

imidazoles, such as 2-methylimidazole, 2-phenylimidazole, etc.,

ammonia, or basic salts such as tetramethylammonium borohydride (Me₄NBH₄), tetrabutylammonium borohydride (Bu₄ NBH₄), tetrabutylammoniumtetraphenylborate (Bu₄ NBPh₄), tetramethylammonium tetraphenylborate(Me₄ NBPh₄), etc.

Of these various compounds, tetraalkyl ammonium hydroxides, inparticular electronic-grade tetraalkyl ammonium hydroxides having lowimpurity metal contents, are preferably used.

Examples of borate compounds (c) include boric acid, and borate estersrepresented by the following general formula,

    B(OR).sub.n (OH).sub.3-n

where R is a methyl, ethyl, or other alkyl group, phenyl or other arylgroup, etc., and n is 1, 2, or 3.

Specific borate esters of this type include trimethyl borate, triethylborate, tributyl borate, trihexyl borate, triheptyl borate, triphenylborate, tritolyl borate, trinaphthyl borate, etc.

Preferred combinations for use as catalysts in accordance with thepresent invent ion include combinations of

(a) an alkali metal compound and/or alkaline-earth metal compound, and

(b) a nitrogen-containing basic compound.

The alkali metal compound and/or alkaline-earth metal compound (a)should be used in the amount specified above. The amount of thenitrogen-containing basic compound (b) used should be 1×10⁻⁶ to 1×10⁻¹mole, preferably 1×10⁻⁵ to 1×10⁻² mole, per mole of aromatic dihydroxycompounds. If the amount of nitrogen-containing basic compound (b) usedis 1×10⁻⁶ to 1×10⁻¹ mole per mole of aromatic dihydroxy compounds, thetransesterification and polymerization reactions will proceed atadequate rates, and the resulting copolymerized polycarbonate will haveexcellent color tone, heat resistance, water resistance, etc.

The use of such a catalyst combination of an alkali metal compoundand/or alkaline-earth metal compound (a) and a nitrogen-containing basiccompound (b) makes it possible to produce high-molecular-weightcopolymerized polycarbonates having excellent transparency, heatresistance, and water resistance, and improved color tone, at highpolymerization activities.

In accordance with the present invention it is preferable to use acatalyst combination of

(a) an alkali metal compound and/or alkaline-earth metal compound, and

(c) boric acid or a borate ester,

or a catalyst combination of

(a) an alkali metal compound and/or alkaline-earth metal compound,

(b) a nitrogen-containing basic compound, and

(c) boric acid or a borate ester.

In such a catalyst combination, the alkali metal compound and/oralkaline-earth metal compound (a), and the nitrogen-containing basiccompound (b), are preferably used in the amounts specified above.

The amount of boric acid or borate ester (c) used should be 1×10⁻⁸ to1×10⁻¹ mole, preferably 1×10⁻⁷ to 1×10⁻² mole, more preferably 1×10⁻⁶ to1×10⁻⁴ mole, per mole of aromatic dihydroxy compounds.

If the amount of boric acid or borate ester (c) used is 1×10⁻⁸ to 1×10⁻¹mole per mole of aromatic dihydroxy compounds, one can obtain acopolymerized polycarbonate which does not tend to show lower molecularweight after heat aging, and has excellent color tone, heat resistance,and water resistance.

In particular, the use of catalysts comprising (a) alkali metalcompounds and/or alkaline-earth metal compounds, (b) nitrogen-containingbasic compounds, and (c) boric acid or borate esters, makes it possibleto produce high-molecular-weight copolymerized polycarbonates havingexcellent transparency, heat resistance, and water resistance, andimproved color tone, at high polymerization activities.

Using this sort of catalyst, the polycondensation reaction of thecarbonate diester with the aromatic dihydroxy compounds includingresorcin and/or substituted resorcins can be carried out underconditions similar to those used in known polycondensation reactions ofcarbonate diesters with aromatic dihydroxy compounds.

Specifically, the aromatic dihydroxy compounds react with the carbonatediesters at atmospheric pressure and a temperature of 80°-250° C.,preferably 100°-230° C., more preferably 120°-190° C., for 0 to 5 hours,preferably 0 to 4 hours, more preferably 0 to 3 hours, after which thepressure in the reaction system is lowered and the temperature increasedas the reaction between aromatic dihydroxy compounds and carbonatediesters proceeds, eventually reaching a pressure of less than 5 mm Hg,preferably less than 1 mm Hg, and a temperature of 240°-320° C., tocause polycondensation of the aromatic dihydroxy compounds with thecarbonate diesters.

This polycondensation may be carried out continuously or batchwise, in atank, tubular, or column reactor.

The copolymerized polycarbonate thus obtained generally has an intrinsicviscosity η! of 0.2-1.2 dL/g, preferably 0.3-1.0 dL/g.

In accordance with the present invention, copolymerized polycarbonateswith high intrinsic viscosities IV! can be produced even when theproportion of resorcin and/or substituted resorcins in the aromaticdihydroxy compounds used is large.

In the method of producing copolymerized polycarbonates in accordancewith the present invention, it is preferred to add an acidic compoundand optionally an epoxy compound to the reaction product, i.e. thecopolymerized polycarbonate, thus obtained.

The acidic compound may be a Lewis acid, a Broensted acid, or an esterof a sulfur-containing strong acid, so long as it is capable ofneutralizing the alkaline compound (alkali metal compound,alkaline-earth metal compound, etc.) used as the catalyst.

A Broensted acid used for this purpose should have a pK_(a) of less than5, preferably less than 3, in aqueous solution at 25° C.

Using an acidic compound having such a pK_(a) value is advantageousbecause it can neutralize the alkali metal or alkaline-earth metal usedas the catalyst, and thus stabilize the resulting copolymerizedpolycarbonate.

Specific examples of Lewis acids include:

boron compounds, such as zinc borate, boron phosphate, etc.,

borate esters, such as B(OCH₃)₃, B(OEt)₃, B(OPh)₃, etc.,

aluminum compounds, such as aluminum stearate, aluminum silicate, etc.,

zirconium compounds, such as zirconium carbonate, zirconium alkoxides,zirconium hydroxycarboxylates, etc.,

gallium compounds, such as gallium phosphide, gallium antimonide, etc.,

germanium compounds, such as germanium oxide, organic germaniumcompounds, etc.,

tin compounds, such as tetra- and hexaorganotin compounds, PhOSn(Bu)₂OSn(Bu)₂ OPh, etc.,

antimony compounds, such as antimony oxide, alkyl antimony compounds,etc.,

bismuth compounds, such as bismuth oxide, alkyl bismuth compounds, etc.,

zinc compounds, such as (CH₃ COO)₂ Zn, zinc stearate, etc., and

titanium compounds, such as alkoxy titanium compounds, titanium oxide,etc.

(In the formulas above, Ph represents a phenyl group, Et an ethyl group,and Bu a butyl group.)

Specific examples of Broensted acids include:

phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoricacid, polyphosphoric acid, boric acid, hydrochloric acid, hydrobromicacid, sulfuric acid, sulfurous acid, adipic acid, azelaic acid,dodecanoic acid, L-ascorbic acid, asparaginic acid, benzoic acid, formicacid, acetic acid, citric acid, glutamic acid, salicylic acid, nicotinicacid, fumaric acid, maleic acid, oxalic acid, benzenesulfinic acid,toluenesulfinic acid, benzenesulfonic acid, p-toluenesulfonic acid,trifluoromethanesulfonic acid, naphthalenesulfonic acid, sulfonatedpolystyrene, methyl acrylatesulfonated styrene copolymers, othersulfonic acids, etc.

Esters of sulfur-containing acids which may be used include dimethylsulfate, diethyl sulfate, methyl, ethyl, butyl, octyl, or phenyl estersof p-toluenesulfonic acid, methyl, ethyl, butyl, or octyl esters ofbenzenesulfonic acid, and other such compounds whose acid groups have apK_(a) of less than 3.

Of these various acidic compounds, those containing sulfur, phosphorus,etc. are preferred. Acidic compounds containing sulfur are particularlypreferred.

The acidic compounds are added to the reaction product in amountssufficient to neutralize or weaken the effect of residual alkalinecompounds on the copolymerized polycarbonate. The amount could be, forexample, 0.01-500 moles, preferably 0.1-100 moles, more preferably0.1-50 moles, most preferably 0.5-30 moles, per mole of residual alkalimetal compound and/or alkaline-earth metal compound in the copolymerizedpolycarbonate.

In particular when the acidic compound is a Lewis acid or a Broenstedacid with a pK_(a) greater than 3, the amount used should be 0.01-500moles, preferably 0.1-50 moles, more preferably 0.1-30 moles. If theacidic compound is a Broensted acid with a pK_(a) of 3 or less, or anester of a sulfur-containing acid, the amount used should be 0.01-500moles, preferably 0.1-15 moles, more preferably 0.1-7 moles.

Epoxy compounds which may be used in accordance with the presentinvention are compounds having one or more epoxy groups per molecule.There is no particular restriction on the amount used, although it isgenerally 0.0001-0.2 wt. part, preferably 0.001-0.1 wt. part, per 100wt. parts of copolymerized polycarbonate in the reaction product.

Specific examples of such epoxy compounds include epoxidized soybeanoil, epoxidized linseed oil, phenyl glycidyl ether, allyl glycidylether, tert-butylphenyl glycidyl ether, 3,4-epoxycyclohexylmethyl3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl3,4-epoxy-6-methylcyclohexanecarboxylate, 2,3-epoxycyclohexylmethyl3,4-epoxycyclohexanecarboxylate, 4-(3,4-epoxy-5-methylcyclohexyl)butyl3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylethylene oxide,cyclohexylmethyl 3,4-epoxycyclohexanecarboxylate,3,4-epoxy-6-methylcyclohexylmethyl 6-methylcyclohexanecarboxylate,bisphenol A diglycidyl ether, tetrabromobisphenol A glycidyl ether,phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester,bisepoxycyclopentadienyl ether, bis-epoxyethylene glycol,bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethyleneepoxide, octyl epoxytalate sic!, epoxidized polybutadiene,3,4-dimethyl-1,2-epoxycyclohexane, 3,5-dimethyl-1,2-epoxycyclohexane,3-methyl-5-tert-butyl-1,2-epoxycyclohexane, octadecyl2,2'-dimethyl-3,4-epoxycyclohexanecarboxylate, n-butyl2,2'-dimethyl-3,4-epoxycyclohexanecarboxylate, cyclohexyl2-methyl-3,4-epoxycyclohexanecarboxylate, n-butyl2-isopropyl-3,4-epoxy-5-methylcyclohexanecarboxylate, octadecyl3,4-epoxycyclohexanecarboxylate, 2-ethylhexyl3',4'-epoxycyclohexanecarboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl3',4'-epoxycyclohexanecarboxylate, 4,5-epoxytetrahydrophthalicanhydride, 3-tert-butyl-4,5-epoxytetrahydrophthalic anhydride, diethyl4,5-epoxy-cis-1,2-cyclohexanedicarboxylate, di-n-butyl-3-tert-butyl4,5-epoxy-cis-1,2-cyclohexanedicarboxylate, etc. These compounds may beused singly or in combinations of two or more.

When acidic and epoxy compounds are added at the same time to thecopolymerized polycarbonate reaction product, any excess acidic compoundis neutralized by reaction with the epoxy compound, and one thus obtainsa copolymerized polycarbonate having excellent color tone, heatresistance, water resistance, etc.

In the method of producing copolymerized polycarbonates in accordancewith the present invention, there is no particular restriction on thetechnique used to add the acidic compound and optionally an epoxycompound to the polycarbonate obtained as the reaction product. Forexample, the acidic compound and optionally an epoxy compound may beadded to the copolymerized polycarbonate in the molten state and kneadedwith it, or the acidic compound and optionally an epoxy compound may beadded to a solution of the copolymerized polycarbonate and stirred.

Once the polycondensation reaction is complete, the acidic and epoxycompounds may be added to the molten copolymerized polycarbonatereaction product either simultaneously or one after the other, either inthe reactor or in an extruder, and then kneaded. It is also possible topelletize the copolymerized polycarbonate, and then feed the acidiccompound and optionally an epoxy compound along with the pellets to asingle-screw or twin-screw extruder to melt knead them with the polymer.Another method is to dissolve the copolymerized polycarbonate in asuitable solvent, such as methylene chloride, chloroform, toluene,tetrahydrofuran, etc., to prepare a solution, and then add the acidiccompound and optionally an epoxy compound to the solution, eithersimultaneously or one after the other, and stir.

When an acidic compound and an epoxy compound are added separately tothe copolymerized polycarbonate, either the acidic compound or the epoxycompound may be added first.

In addition to such acidic compounds and epoxy compounds, it is alsopossible in accordance with the present invention to add the usual heatstabilizers, Tinuvin ultraviolet absorbers, mold release agents,antistatic agents, slip agents, antiblocking agents, lubricants,antifogging agents, dyes, pigments, natural oils, synthetic oils, waxes,organic fillers, inorganic fillers, etc. to the copolymerizedpolycarbonate in amounts which do not interfere with the object of thepresent invention.

Specific examples of such heat stabilizers include phenolic stabilizers,organic thio ether stabilizers, organic phosphite stabilizers, hinderedamine stabilizers, and epoxy stabilizers.

Phenolic stabilizers include, for example, n-octadecyl3-(4-hydroxy-3',5'-di-tert-butylphenyl)propionate, tetrakismethylene-3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionato!methane,1,1,3-tris(2-methyl-4-hydroxy-5- tert-butylphenyl)butane, distearyl(4-hydroxy-3-methyl-5-tert-butyl)benzylmalonate,4-hydroxymethyl-2,6-di-tert-butylphenol, etc. These may be used singlyor in combinations of two or more.

Thio ether stabilizers include, for example, dilauryl thiodipropionate,distearyl thiodipropionate, dimyristyl 3,3'-thiodipropionate, ditridecyl3,3'-thiodipropionate, pentaerythritol tetrakis(β-laurylthiopropionate),etc. These may be used singly or in combinations of two or more.

Phosphorus-containing stabilizers include, for example:

aryl alkyl phosphites such as bis(2,4-di-tert-butylphenyl)pentaerythrityl diphosphite, diphenyl decyl phosphite, diphenyl isooctylphosphite, phenyl isooctyl phosphite, 2-ethylhexyl diphenyl phosphite,etc.,

trialkyl phosphites such as trimethyl phosphite, triethyl phosphite,tributyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecylphosphite, trioctadecyl phosphite, distearyl pentaerythrityldiphosphite, tris(2-chloroethyl) phosphite, tris(2,3-dichloropropyl)phosphite, etc.,

tricycloalkyl phosphites such as tricyclohexyl phosphite, etc.,

triaryl phosphites such as triphenyl phosphite, tricresyl phosphite,tris(ethylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite,tris(nonylphenyl) phosphite, tris(hydroxyphenyl) phosphite, etc.,

trialkyl phosphates such as trimethyl phosphate, triethyl phosphate,tributyl phosphate, trioctyl phosphate, tridecyl phosphate, trioctadecylphosphate, distearyl pentaerythrityl diphosphate, tris(2-chloroethyl)phosphate, tris(2,3-dichloropropyl) phosphate, etc.,

tricycloalkyl phosphates such as tricyclohexyl phosphate, etc., and

triaryl phosphates such as triphenyl phosphate, tricresyl phosphate,tris(nonylphenyl) phosphate, 2'-ethylphenyl diphenyl phosphate, etc.These may be used singly or in combinations of two or more.

Hindered amine stabilizers include, for example,bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate,bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 1-2-{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy}ethyl!-4-{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy}-2,2,6,6-tetramethylpiperidine,8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,2,3-triazaspiro.sup. 4,5!undecan-2,4-dione, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine,bis(1,2,2,6,6-pentamethyl-4-piperidinyl)2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonate,tetrakis(2,2,6,6-tetramethyl-4-piperidinyl)1,2,3,4-butanetetracarboxylate, etc. These may be used singly or incombinations of two or more.

The amount of such heat stabilizers used should generally be 0.001-5 wt.parts, preferably 0.005-0.5 wt. part, more preferably 0.0-0.3 wt. part,per 100 wt. parts of the copolymerized polycarbonate.

These heat stabilizers may be added either in solid or liquid form.

In order to reduce the number of times the copolymerized polycarbonatehas to be reheated, these heat stabilizers are preferably added whilethe copolymerized polycarbonate Is still in molten form, anywhere fromthe final polymerization reactor to the point at which the product iscooled and pelletized. Because the copolymerized polycarbonate containsheat stabilizers, thermal decomposition of the polymer will be inhibitedduring subsequent reheating and processing, such as extrusion orpelletizing operations.

One can also add ultraviolet absorbers at the same time as the heatstabilizers. There is no particular restriction on the type ofultraviolet absorber used. It may be any of the common ultravioletabsorbers, such as a salicylate ultraviolet absorber, a benzophenoneultraviolet absorber, a benzotriazole ultraviolet absorber, acyanoacrylate ultraviolet absorber, etc.

Specific examples of salicylate ultraviolet absorbers include phenylsalicylate, p-tert-butylphenyl salicylate, etc.

Benzophenone ultraviolet absorbers include 2,4-dihydroxybenzophenone,2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone,2,2'-dihydroxy-4,4'-dimethoxybenzophenone,2-hydroxy-4-methoxy-2'-carboxybenzophenone,2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate,2-hydroxy-4-n-octoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone,4-dodecyloxy-2-hydroxybenzophenone,bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane,2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, etc.

Examples of benzotriazole ultraviolet absorbers include2-(2'-hydroxy-5'-methylphenyl)benzotriazole,2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole,2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl )-5-chlorobenzotriazole,2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole,2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole,2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole, 2-2'-hydroxy-3'-(3',4',5',6'-tetrahydrophthalimidomethyl)-5'-methylphenyl!benzotriazole,2,2'-methylenebis4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol!, etc.

Cyanoacrylate ultraviolet absorbers include 2-ethylhexyl2-cyano-3,3-diphenylacrylate, ethyl 2-cyano3,3-diphenylacrylate, etc.They may be used singly or in combinations of two or more.

The amount of ultraviolet absorbers used is ordinarily 0.001-5 wt.parts, preferably 0.005-1 wt. part, more preferably 0.01-0.5 wt. part,per 100 wt. parts of the copolymerized polycarbonate.

In accordance with the present invention, mold release agents may alsobe added at the same time as the heat stabilizers described above. Thereis no particular restriction on the type of mold release agent used; itmay be any of the common mold release agents. Examples include:

hydrocarbon mold release agents, such as natural and syntheticparaffins, polyethylene waxes, fluorocarbons, etc.,

fatty acid mold release agents, such as stearic acid, hydroxystearicacid, other higher fatty acids, hydroxy fatty acids, etc.,

fatty amide mold release agents, such as stearamide,ethylenebisstearamide, other alkylene bis fatty amides, etc.,

alcohol mold release agents, such as stearyl alcohol, cetyl alcohol,other fatty alcohols, polyhydric alcohols, polyglycole, polyglycerols,etc.

fatty acid ester mold release agents, such as butyl stearate,pentaerythritol tetrastearate, other fatty acid esters of loweralcohols, fatty acid esters of polyhydric alcohols, fatty acid eaters ofpolyglycols, etc., and

silicone mold release agents, such as silicone oils, etc.

These agents may be used singly or in combinations of two or more. Theamount of mold release agent used is ordinarily 0.001-wt. parts,preferably 0.005-1 wt. part, more preferably 0.01-0.5 wt. part, per 100wt. parts of the polycarbonate.

Colorants can also be added at the same time as the heat stabilizersdiscussed above. The colorants may be either pigments or dyes. Inorganicor organic colorants, or combinations of both types, can be used.

Specific examples of inorganic colorants include oxides such as titaniumdioxide and iron oxide red, hydroxides such as alumina white, sulfidessuch as zinc sulfide, selenides, ferrocyanides such as Prussian Blue,chromate salts such as zinc chromate and Molybden Red, sulfate saltssuch as barium sulfate, carbonate salts such as calcium carbonate,silicate salts such as ultramarine, phosphate salts such as ManganeseViolet, carbon in forms such as carbon black, metal powder pigments suchas bronze powder and aluminum powder, etc.

Specific examples of organic colorants include nitroso compounds such asNaphthol Green B, nitro compounds such as Naphthol Yellow S, azocompounds such as Resol Red, Bordeaux 10B, Naphthol Red, and CromophthalYellow, phthalocyanine compounds such as Phthalocyanine Blue and FastSky Blue, and condensed polycyclic colorants such as Indanthrone Blue,Quinacridone Violet, and Dioxazine Violet, etc.

These colorants may be used singly or in combinations of two or more.

The amount of such colorants used is ordinarily 1×10⁻⁶ to 5 wt. parts,preferably 1×10⁻⁵ to 3 wt. parts, more preferably 1×10⁻⁵ to 1 wt. part,per 100 wt. parts of the copolymerized polycarbonate.

In accordance with the present invention, the copolymerizedpolycarbonate obtained by the polycondensation reaction is preferablysubjected to a vacuum treatment following the addition of the acidiccompound and optionally an epoxy compound.

There is no particular restriction on the apparatus used for such vacuumtreatment. For example, one may use a reactor having a vacuum apparatusattached to it, or an extruder with a vacuum apparatus attached.

When a reactor is used, it may be a vertical tank reactor or ahorizontal tank reactor, although horizontal tank reactors arepreferred.

Vacuum treatment in such a reactor is performed at a pressure of0.05-750 mm Hg, preferably 0.05-5 mm Hg.

If vacuum treatment is carried out using an extruder, it is preferablyperformed for a period of approximately 10 seconds to 15 minutes. In areactor, on the other hand, the treatment time is preferably from about5 minutes to 3 hours. Vacuum treatment is preferably performed at atemperature of approximately 240°-350° C.

When vacuum treatment is carried out using an extruder, either a ventedsingle-screw extruder or a vented twin-screw extruder may be used. Thepolymer can also be pelletized at the same time.

When vacuum treatment Is carried out in an extruder, it can be performedat a pressure of 1-750 mm Hg, preferably 5-700 mm Hg.

Thus, by adding an acidic compound and optionally an epoxy compound tothe copolymerized polycarbonate reaction product, then subjecting it tovacuum treatment, one can obtain a copolymerized polycarbonate havinglower residual monomer and oligomer contents,

In copolymerized polycarbonates obtained in this way, the constituentunits derived from resorcin and/or substituted resorcins are representedby the following formula III!, while the constituent units formed fromaromatic dihydroxy compounds other than resorcin and/or substitutedresorcins are represented by the general formula IV!, ##STR4##

R and n in formula III! are as in formula I! above, and R⁴, R⁵, p, and qin formula IV! are as in formula III! above.

Copolymerized polycarbonates obtained in accordance with the presentinvention contain 2-90 mole %, preferably 5-70 mole %, more preferably10-60 mole %, constituent units derived from resorcin and/or substitutedresorcins, where the total of all constituent units derived fromaromatic dihydroxy compounds is taken as 100 mole %. Constituent unitsderived from aromatic dihydroxy compounds other than resorcin and/orsubstituted resorcins make up 98-10 mole %, preferably 95-30 mole %,more preferably 90-40 mole %, of the total.

Such copolymerized polycarbonates contain a random distribution ofconstituent units derived from the resorcin and/or substituted resorcinsand carbonate diesters, and constituent units derived from the otheraromatic dihydroxy compounds and carbonate diesters.

Copolymerized polycarbonates obtained in accordance with the presentinvention may also contain polyester-polycarbonate units of the typementioned above, in amounts which do not interfere with the object ofthe present invention. Specifically, they may contain up to 50 mole %,preferably not more than 30 mole %, polyester-polycarbonate units.

Copolymerized polycarbonates obtained in accordance with the presentinvention may also contain constituent units derived from the sort ofpolyfunctional compounds described above, in amounts which do notinterfere with the object of the present invention. Specifically, theremay be up to 0.03 mole of such units, preferably 0.001-0.02 mole, morepreferably 0.001-0.01 mole, of such units per mole of copolymerizedpolycarbonate.

Copolymerized polycarbonates obtained in accordance with the presentinvention usually have glass transition temperatures (T_(g)) of100°-150° C., preferably 110°-135° C.

Their thermal decomposition temperatures are usually 350°-380° C.,preferably 360°-380° C.

They usually have melt flow rates (MFR) (measured by the JIS K 7210standard method, at a temperature of 280° C. and a load of 1.2 kg) of5-30 g/10 min, preferably 8-20 g/10 min.

Copolymerized polycarbonates obtained in accordance with the presentinvention have excellent melt flow and formability, in addition to goodmechanical properties, heat resistance, transparency, and color tone.Because such copolymerized polycarbonates can be fabricated usingshorter melt processing times, they can be used to make copolymerizedpolycarbonate products with excellent properties which show little or noeffects from the heat used in fabricating them, in addition to theadvantages of shorter molding cycle times and better productivity.

The higher the proportion of constituent units derived from resorcinand/or substituted resorcins, the better the sliding characteristics ofthe copolymerized polycarbonates. On the other hand, if the proportionof such units is lower, the water resistance of the polymer is better,as is its stability during prolonged holdup in melt forming operations.

Copolymerized polycarbonates in accordance with the present inventionalso give molded products which show excellent weather resistance andcolor stability during prolonged use, so they are well suited for use inoptical applications such as sheets, lenses, compact disks, etc.,automobile parts and other outdoor applications, as well as applicationssuch as instrument housings, etc.

Copolymerized polycarbonates obtained in accordance with the presentinvention not only have thermal decomposition temperatures as high asthose of ordinary polycarbonates, but also show good chemicalresistance, including to gasoline. They are thus suitable for moldinginto automobile engine parts.

Some impairment of transparency or color tone may occur if aromaticdihydroxy compounds including resorcin and/or substituted resorcins aremade to react directly with phosgene to obtain a copolymerizedpolycarbonate having constituent units derived from resorcin and/orsubstituted resorcins. In such an interfacial polymerization process, italso tends to be difficult to obtain copolymerized polycarbonates havinghigh intrinsic viscosity IV! if the aromatic dihydroxy compounds includea high proportion of resorcin and/or substituted resorcins.

EFFECT OF INVENTION

The method of producing copolymerized polycarbonates in accordance withthe present invention can be used to make copolymers containing 2-90mole % constituent units derived from resorcin and/or substitutedresorcins. Copolymerized polycarbonates obtained by this method haveimproved flow and formability in addition to excellent mechanicalproperties, heat resistance, chemical resistance, transparency, andcolor tone.

In the method of the present invention, if the copolymerizedpolycarbonate reaction product is also treated with acidic compounds andoptionally epoxy compounds, the effect of residual alkaline compoundcatalysts in the product Is neutralized or weakened, and the epoxycompounds serve to diminish any adverse effects of the acidic compounds.Thus, the method of the present invention makes it possible to suppressadverse effects of the catalyst, and produce copolymerizedpolycarbonates having excellent heat resistance, water resistance, andweather resistance, as well as good stability when held for long periodsof time in the molten state.

The present invention will now be explained by means of some examples,although it is by no means limited to the examples described here.

EXAMPLES

The following test methods were used for property measurements:

Intrinsic Viscosity (IV) dL/g!: measured with an Ube-rode viscometer, inmethylene chloride solution at 20° C.

Melt Flow Rate (MFR) g/10 min!: measured by the JIS K-7210 standardmethod, at 300° C. with a load of 1.2 kg

Color Tone (YI): Test plates 3 mm thick were formed by injection moldingat cylinder temperature 290° C., injection pressure 1000 kg/cm², cycletime 45 sec, and mold temperature 100° C. The X, Y and Z values for eachplate were measured by the transmission method using a Color and ColorDifference Meter ND-1001 DP (from Nippon Denshoku Kogyo). The yellownessindex (YI) was obtained from the measured values as follows.

    YI=100(1.277X-1.060Z)/Y

Light Transmission: measured by the ASTM D 1003 standard method, usingthe same injection-molded test plates as in the color tone measurements

Haze: measured with an NDH-200 meter (from Nippon Denshoku Kogyo) usingthe same injection-molded test plates as in the color tone measurements

Holdup Stability: The resin was injection molded after being held up inthe molding machine at a cylinder temperature of 320° C. for 15 minutes,and the YI and MFR of the resulting test plates were measured.

Example 1

A charge of 0.300 mole of bisphenol A (from Nihon GE Plastics Ltd.),0.300 mole of resorcin (from Mitsui Sekiyu Kagaku Kogyo Ltd.), and 0.672mole diphenyl carbonate (from Enii Co.) was placed in a 500-mL glassreactor, blanketed with nitrogen, and heated to 180° C. with stirring bya nickel agitator for 30 minutes. Then 91.2 mg of a 15% aqueous solutionof tetramethylammonium hydroxide (2.5×10⁻⁴ mole/mole bisphenol A) and19.2 mg of a 0.1% aqueous solution of sodium hydroxide (0.004×2.5×10⁻⁴mole/mole bisphenol A) were added, and the contents stirred for 30minutes to effect transesterification.

Then the temperature in the reactor was raised to 210° C. as thepressure was gradually lowered to 200 mm Hg and held at that value for 1hour, after which the temperature was raised to 240° C. (still at 200 mmHg) for 20 minutes, then the pressure was gradually lowered to 150 mm Hgand held for 20 minutes, then to 100 mm Hg for 20 minutes, and to 15 mmHg for 0.5 hour, then the temperature was raised to 270° C. and thepressure lowered to 0.5 mm Hg, and the reaction allowed to continue for2 hours.

After 2 hours the reactor was again blanketed with nitrogen, 5.472 mg ofa 5% toluene solution of butyl p-toluenesulfonate (0.008×2.5×10.sup.×4mole/mole bisphenol A) was added, and the reactor contents were stirredfor 30 minutes at 0.5 mm Hg, then formed into pellets.

The resulting copolymerized polycarbonate had an intrinsic viscosity(IV) of 0.49 dL/g).

The results are listed in Table 1.

Example 2

The procedure in Example I was repeated using 0.450 mole of bisphenol A(from Nihon GE Plastics Ltd.) and 0.150 mole of resorcin (from MitsuiSekiyu Kagaku Kogyo Ltd.), to obtain copolymerized polycarbonatepellets. The results are listed in Table 1.

Example 3

A charge of 0.300 mole of bisphenol A (from Nihon GE Plastics Ltd.),0.300 mole of resorcin (from Mitsui Sekiyu Kagaku Kogyo Ltd.), 0.672mole diphenyl carbonate (from Enii Co.), and 3.0 mg of a 3% aqueoussolution of boric acid (0.1×2.5×10⁻⁴ mole/mole bisphenol A) was placedin a 500-mL glass reactor, blanketed with nitrogen, and heated to 180°C. with stirring by a nickel agitator for 30 minutes. Then 91.2 mg of a15% aqueous solution of tetramethylammonium hydroxide (2.5×10⁻⁴mole/mole bisphenol A) and 19.2 mg of a 0.1% aqueous solution of sodiumhydroxide (0.004×2.5×10⁻⁴ mole/mole bisphenol A) were added, and thecontents stirred for 30 minutes to effect transesterification.

Then the temperature in the reactor was raised to 210° C. as thepressure was gradually lowered to 200 mm Hg and held at that value for 1hour, after which the temperature was raised to 240° C. (still at 200 mmHg) for 20 minutes, then the pressure was gradually lowered to 150 mm Hgand held for 20 minutes, then to 100 mm Hg for 20 minutes, and to 15 mmHg for 0.5 hour, then the temperature was raised to 270° C. and thepressure lowered to 0.5 mm Hg, and the reaction allowed to continue for2 hours.

The resulting copolymerized polycarbonate had an intrinsic viscosity(IV) of 0.48 dL/g). The results are listed in Table 1.

Examples 4-8

The procedure in Example 1 was repeated, except that afterpolymerization the compounds listed in Table 1 were added as stabilizersin the amounts indicated, and kneaded with the copolymerizedpolycarbonates before they were formed into pellets. The results arelisted in Table 1.

Comparison 1

The procedure in Example 1 was repeated using 0.600 mole of bisphenol A(from Nihon GE Plastics Ltd.) and no resorcin, to obtain apolycarbonate.

The results are shown in Table 1.

Comparison 2

The procedure in Comparison 1 was repeated using the type and amount ofheat stabilizer listed in Table 1, to obtain a polycarbonate.

The results are listed in Table 1.

Comparison 3

The properties of a bisphenol A polycarbonate (Lexan LS2-111, from NihonGE Plastics Ltd.) were measured.

The results are listed in Table 1.

Examples 9-10

The procedure in Example 1 was repeated using the amounts of bisphenol Aand resorcin listed in Table 1, with a total polymerization time of 1.5hours, and with addition of the stabilizers indicated in the table, toobtain copolymerized polycarbonate pellets. The results are listed inTable 1.

Example 11

The procedure in Example 1 was repeated, except that 240 mg of a 10%aqueous solution of sodium hydroxide (5×2.5×10⁻⁴ mole/mole bisphenol A)was added, the pressure was ultimately lowered to 0.5 mm Hg, and thereaction was allowed to go on for 1 hour, to obtain copolymerizedpolycarbonate pellets.

Comparison 4

The procedure in Example 1 was repeated, using the amount of bisphenol Aindicated in Table 1, and a total polymerization time of 1.5 hours. Thecompounds listed in the table were added as stabilizers afterpolymerization, and kneaded with the reaction product, to formcopolymerized polycarbonate pellets. The results are listed in Table 1.

Comparison 5

The properties of a bisphenol A polycarbonate (High Flow Grade, fromNihon GE Plastics Ltd.) were measured.

The results are listed in Table 1.

Comparison 6

A mixture of 0.5 mole of bisphenol A, 0.5 mole of resorcin, 114 g ofsodium hydroxide, 1300 mL of water, and 1620 mL of methylene chloridewas charged to a 5-liter polymerization flask, then 96 g of NaOH, 1820mL of water, and 114 mg of triethylbenzylammonium bromide were added,and the flask contents were stirred at 1200 rpm at 25° C. as phosgenewas bubbled in, and the pH of the reaction mixture was adjusted to 11 asthe reaction continued for 2 hours.

A precipitate was observed to form during the reaction. After completionof the reaction, the polymerization flask was purged with nitrogen for15 minutes to remove any remaining phosgene. The methylene chloridelayer containing the precipitate was recovered in a separatory funnel,adjusted to pH 1 with concentrated hydrochloric acid, and then washedwith water until it became neutral. The resulting methylene chloridesolution was poured into 20 liters of methanol to precipitate thepolymer.

The polymer had an IV of only 0.30 dL/g. Its other properties could notbe measured.

The stabilizers used, as indicated in Table 1, were the following:

Irganox 168, from Ciba-Geigy

Mark A0-50, from Adeka-Argus

Cyasorb UV-5411, from Sun Chemical

TSF 437, from Toshiba Silicone

Plast Violet 8840, from Bayer

                                      TABLE 1    __________________________________________________________________________                    Example 1                           Example 2                                  Example 3                                         Example 4                                                Example 5    __________________________________________________________________________    Bisphenol A/Resorcin                    50/50  75/25  50/50  50/50  75/25    (mole ratio in feed)    Acidic          Butyl  Butyl  --     Butyl  Butyl    Compound        ρ-toluene-                           ρ-toluene-                                         ρ-toluene-                                                ρ-toluene-    Added           sulfonate                           sulfonate     sulfanate                                                sulfonate    (moles/mole alkali metal)                    2      2      --     2      2    Epoxy Compound  0      0      0      0.05   0.05    Celloxide 2021P (Daicel)    (g/100 g polymer)    Additives    (g/100 g polymer)    Irganox 168 (Ciba-Geigy)                    0      0      0      0.05   0.05    Mark A0-50 (Adeka-Argus)                    0      0      0      0.05   0.05    Cyasorb UV-5411 (Sun Chem)                    0      0      0      0.3    0.3    TSF 437 (Toshiba Silicone)                    0      0      0      0.3    0.3    Plast Violet 8840 (Bayer)                    0      0      0      0.00006                                                0.00006    Initial Properties    Intrinsic Viscosity (dL/g)                    0.49   0.49   0.48   0.49   0.49    MFR (g/10 min)  20     15     21     21     16    Color Tone (YI) 2.1    2.0    2.0    0.7    0.6    Light Transmission (%)                    90.8   90.8   90.6   89.6   89.6    Haze            0.4    0.3    0.4    0.4    0.3    Holdup Stability    MFR (g/10 min)  23     17     26     25     18    MFR Increase (%)                    15     10     20     20     15    Color Tone (YI) 2.4    2.3    2.4    1.0    0.9    Light Transmission (%)                    90.7   90.7   90.4   89.6   89.6    Heat Resistance HDT (°C.)                    111    123    110    111    123    Heat Aging Resistance                    44     37     52     28     13    Color Tone (YI)    Water Resistance Haze                    51     2      54     61     4    __________________________________________________________________________                   Example 6                         Example 7                               Example 8                                     Example 9                                           Example 10                                                 Example 11    __________________________________________________________________________    Bisphenol A/Resorcin                   85/15 90/10 85/15 85/15 90/10 50/50    (mole ratio in feed)    Acidic         Butyl Butyl Butyl Butyl Butyl Butyl    Compound       ρ-toluene-                         ρ-toluene-                               ρ-toluene-                                     ρ-toluene-                                           ρ-toluene-                                                 ρ-toluene-    Added          sulfonate                         sulfonate                               sulfonate                                     sulfonate                                           sulfonate                                                 sulfonate    (moles/mole alkali metal)                   2     2     2     2     2     2    Epoxy Compound 0     0     0.05  0.05  0.05  0.05    Celloxide 2021P (Daicel)    (g/100 g polymer)    Additives    (g/100 g polymer)    Irganox 168 (Ciba-Geigy)                   0     0     0.05  0.05  0.05  0.05    Mark A0-50 (Adeka-Argus)                   0     0     0.05  0.05  0.05  0.05    Cyasorb UV-5411 (Sun Chem)                   0     0     0.3   0.3   0.3   0.3    TSF 437 (Toshiba Silicone)                   0     0     0.3   0.3   0.3   0.3    Plast Violet 8840 (Bayer)                   0     0     0.00006                                     0.00006                                           0.00006                                                 0.00006    Initial Properties    Intrinsic Viscosity (dL/g)                   0.49  0.49  0.49  0.42  0.42  0.49    MFR (g/10 min) 13    12    14    37    32    21    Color Tone (YI)                   1.9   1.8   0.6   0.6   0.6   4.1    Light Transmission (%)                   90.8  90.8  89.7  89.7  89.7  90.5    Haze           0.4   0.3   0.3   0.3   0.3   0.4    Holdup Stability    MFR (g/10 min) 14    13    15    41    35    27    MFR Increase (%)                   10    10    10    10    10    30    Color Tone (YI)                   2.2   2.2   0.9   0.9   0.9   4.7    Light Transmission (%)                   90.7  90.7  90.1  90.1  90.1  90.4    Heat Resistance HDT (°C.)                   130   131   130   130   131   110    Heat Aging Resistance                   36    35    12    11    11    55    Color Tone (YI)    Water Resistance Haze                   1     1     4     4     4     72    __________________________________________________________________________                    Comp. 1                          Comp. 2                                Comp. 3                                     Comp. 4                                           Comp. 6                                                Comp. 6    __________________________________________________________________________    Bisphenol A/Resorcin                    100/0 100/0 100/0                                     100/0 100/0                                                50/50    (mole ratio in feed)    Acidic          Butyl Butyl --   Butyl --   Butyl    Compound        ρ-toluene-                          ρ-toluene-                                     ρ-toluene-                                                ρ-toluene-    Added           sulfonate                          sulfonate  sulfonate  sulfonate    (moles/mole alkali metal)                    2     2     --   2     --   2    Epoxy Compound  0     0.05  --   0.05  --   --    Celloxide 2021P (Daicel)    (g/100 g polymer)    Additives    (g/100 g polymer)    Irganox 168 (Ciba-Geigy)                    0     0.05  --   0.05  --   --    Mark A0-50 (Adeki-Argus)                    0     0.05  --   0.05  --   --    Cyasorb UV-5411 (Sun Chem)                    0     0.3   --   0.3   --   --    TSF 437 (Toshiba Silicone)                    0     0.3   --   0.3   --   --    Plast Violet 8840 (Bayer)                    0     0.00006                                --   0.00006                                           --   --    Initial Properties    Intrinsic Viscosity (dL/g)                    0.49  0.49  0.49 0.42  0.42 0.3    MFR (g/10 min)  10    11    11   27    27   *    Color Tone (YI) 1.8   0.6   0.5  0.6   0.6  **    Light Transmission (%)                    90.8  89.7  89.6 89.7  89.7 **    Haze            0.3   0.3   0.4  0.3   0.3  **    Holdup Stability    MFR (g/10 min)  11    13    17   31    34   *    MFR Increase (%)                    5     15    55   15    25   *    Color Tone (YI) 2.2   0.9   1.1  0.9   1.2  **    Light Transmission (%)                    90.4  90.3  90.3 90.4  90.3 **    Heat Resistance HDT (°C.)                    135   135   135  132   132  **    Heat Aging Resistance                    35    11    27   11    28   **    Color Tone (YI)    Water Resistance Haze                    0.8   4     70   4     80   **    __________________________________________________________________________     *(impossible to measure)     **(impossible to injection mold)

We claim:
 1. An improved method for copolymerizing polycarbonate by melt polycondensing two or more aromatic dihydroxy compounds with from 1.0 to 1.3 moles of a carbonate diester per mole of aromatic-dihydroxy compound in the presence of a catalyst selected from the group consisting of alkali metal compounds and alkaline-earth metal compounds wherein the improvement comprises melt-polycondensing aromatic dihydroxy compounds wherein resorcin, substituted resorcins or mixtures thereof are 2-90 mole % of the aromatic dihydroxy compounds at atmospheric pressure and at a temperature of from 80° C. to 250° C. for from 0 to 5 hours and then at a reduced pressure of less than 5 mm Hg and a temperature of from 240° C. to 320° C. and adding thereto an acidic compound whereby the copolymerized polycarbonate contains the residual catalyst but has a glass transition temperature in the range of from 100° C. to 150° C., a thermal decomposition temperature in the range of from 350° C. to 380° C. and a melt flow rate at a temperature of 280° C. and under a load of 1.2 kg of from 5 to 30 g/10 min.
 2. The method of claim 1 wherein an epoxy compound is also added to the copolymerized polycarbonate.
 3. An improved method for copolymerizing polycarbonate prepared by melt polycondensing two or more aromatic dihydroxy compounds with from 1.0 to 1.3 moles of a carbonate diester per mole of aromatic dihydroxy compound in the presence of a catalyst selected from the group consisting of alkali metal compounds and alkaline-earth metal compounds wherein the improvement comprises melt-polycondensing aromatic dihydroxy compounds wherein resorcin, substituted resorcins or mixtures thereof are 2-90 mole % of the aromatic dihydroxy compounds, at atmospheric pressure and at a temperature of from 80° C. to 250° C. for from 0 to 5 hours and then at reduced pressure of less than 5 mm Hg and a temperature of from 240° C. to 320° C., adding thereto an acidic compound and then vacuum treating the melted copolymerized polycarbonate whereby the copolymerized polycarbonate contains the residual catalyst but has a glass transition temperature in the range of from 100° C. to 150° C., a thermal decomposition temperature in the range of from 350° C. to 380° C. and a melt flow rate at a temperature of 280° C. and under a load of 1.2 kg of from 5 to 30 g/10 min.
 4. The method of claim 3 wherein an epoxy compound is also added to the copolymerized polycarbonate before vacuum treatment.
 5. A method of producing a copolymerized polycarbonate comprising melt polycondensing two or more aromatic dihydroxy compounds, from 2 to 90 mole % of which are resorcin or substituted resorcins, with from 1.0 to 1.3 moles of a carbonate diester per mole of aromatic dihydroxy compound in the presence of an alkali metal or an alkaline-earth metal catalyst at atmospheric pressure and at a temperature of from 80° C. to 250° C. for from 0 to 5 hours and then at a reduced pressure of less than 5 mm Hg and a temperature of from 240° C. to 320° C., and adding to the melt polycondensation product an acidic compound in an amount sufficient to neutralize the effect of any residue from the alkali metal or alkaline-earth metal catalyst on the copolymerized polycarbonate.
 6. A method of claim 5 which further comprises vacuum treating the melt polycondensation product at a pressure of from 0.05 to 750 mm Hg at a temperature of from 240° to 350° C. after addition of the acidic compound.
 7. A method of claim 5 wherein the catalyst further comprises from 1×10⁻⁶ to 1×10⁻¹ moles of a nitrogen-containing basic compound per mole of aromatic hydroxy compound or from 1×10⁻⁶ to 1×10⁻¹ moles of boric acid or a borate ester per mole of aromatic dihydroxy compound.
 8. A method of claim 7 wherein the catalyst further comprises both the nitrogen-containing basic compound and boric acid or a borate ester. 